The Drop Hat shade is made from a flat steel disc that is available in five different finishes – black, white, brass, chrome and copper.
The piece can be slotted into a Plumen pendant cap to sit just above the light bulb.
The shiny underside of the shade reflects the light emitted by the bulb and provides subtle colour effects.
"We made the discs flat and perfectly proportioned for Plumen bulbs," said company founder and creative director Nicolas Roope. "The lamp holder is hidden by the drop cap, so only the lit part of the bulb projects out, and is met with a perfect reflection."
"From certain angles the original and mirrored form combine into a single glowing sculpture that seems to hover in space," he added. "The scale of the Drop Hat's circular plane gives it a strong presence and when used in series creates a striking architectural gesture, suggesting ceiling plains and defining clear zones in open spaces."
The company said that the addition of the Drop Hat means there are now 145 different possible combinations of bulbs, pendants and shades in its range. There are currently three bulb designs available, alongside six pendant colours and two shades.
Plumen is showcasing its new shades at venues including The Old Les Trois Garcons in Shoreditch and Somerset House during this year's London Design Festival, which continues until 27 September 2015.
Also at Somerset House during the event, Max Lamb has filled a gallery with logs sourced from his grandfather's old ash tree and Patternity has installed a black and white "playground" in one of the rooms.